Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, 85764 Oberschleißheim, Germany; Immunology Unit, University of Veterinary Medicine, 30559 Hannover, Germany.
Clinic for Ruminants with Ambulatory and Herd Health Services, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, 85764 Oberschleißheim, Germany; Clinic for Swine, Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine, 30173 Hannover, Germany.
J Dairy Sci. 2019 Nov;102(11):9983-9994. doi: 10.3168/jds.2018-16171. Epub 2019 Sep 11.
The susceptibility of animals to periparturient diseases has a great effect on the economic efficiency of dairy industries, on the frequency of antibiotic treatment, and on animal welfare. The use of selection for breeding cows with reduced susceptibility to diseases offers a sustainable tool to improve dairy cattle farming. Several studies have focused on the association of distinct bovine chromosome 18 genotypes or haplotypes with performance traits. The aim of this study was to test whether selection of Holstein Friesian heifers via SNP genotyping for alternative paternal chromosome 18 haplotypes associated with favorable (Q) or unfavorable (q) somatic cell scores influences postpartum reproductive and metabolic diseases. Thirty-six heifers (18 Q and 18 q) were monitored from 3 wk before calving until necropsy on d 39 (± 4 d) after calving. Health status and rectal temperature were measured daily, and body condition score and body weight were assessed once per week. Blood samples were drawn twice weekly, and levels of insulin, nonesterified fatty acids, insulin-like growth factor-I, growth hormone, and β-hydroxybutyrate were measured. Comparisons between the groups were performed using Fisher's exact test, chi-squared test, and the GLIMMIX procedure in SAS. Results showed that Q-heifers had reduced incidence of metritis compared with q-heifers and were less likely to develop fever. Serum concentrations of β-hydroxybutyrate were lower and insulin-like growth factor-I plasma concentrations were higher in Q- compared with q-heifers. However, the body condition score and withers height were comparable between haplotypes, but weight loss tended to be lower in Q-heifers compared with q-heifers. No differences between the groups were detected concerning retained fetal membranes, uterine involution, or onset of cyclicity. In conclusion, selection of chromosome 18 haplotypes associated with a reduced somatic cell score resulted in a decreased incidence of postpartum reproductive and metabolic diseases in this study. The presented data add to the existing knowledge aimed at avoiding negative consequences of genetic selection strategies in dairy cattle farming. The underlying causal mechanisms modulated by haplotypes in the targeted genomic region and immune competence necessitate further investigation.
动物对围产期疾病的易感性对奶制品行业的经济效益、抗生素治疗的频率和动物福利有很大影响。利用选择来培育对疾病敏感性降低的奶牛是提高奶牛养殖可持续性的一种工具。已有多项研究集中于不同的牛 18 号染色体基因型或单倍型与生产性能的关联。本研究旨在检测通过 SNP 基因分型选择荷斯坦弗里生小母牛的不同父本 18 号染色体单倍型（与有利的（Q）或不利的（q）体细胞评分相关）是否会影响产后繁殖和代谢疾病。36 头小母牛（18Q 和 18q）从产前 3 周开始监测，直到产后 39 天（±4d）进行剖检。每天测量健康状况和直肠温度，每周评估一次体况评分和体重。每周采集两次血样，测量胰岛素、非酯化脂肪酸、胰岛素样生长因子-I、生长激素和β-羟丁酸水平。使用 Fisher 确切检验、卡方检验和 SAS 中的 GLIMMIX 程序对两组进行比较。结果表明，与 q 小母牛相比，Q 小母牛的子宫炎发病率降低，发热的可能性较小。与 q 小母牛相比，Q 小母牛的血清β-羟丁酸浓度较低，胰岛素样生长因子-I 血浆浓度较高。然而，两组之间的体况评分和肩高相当，但 Q 小母牛的体重减轻量低于 q 小母牛。两组之间在胎衣不下、子宫复旧或发情开始方面没有差异。结论：选择与体细胞评分降低相关的 18 号染色体单倍型可降低本研究中小母牛产后繁殖和代谢疾病的发生率。所提供的数据增加了旨在避免奶牛养殖中遗传选择策略产生负面影响的现有知识。该目标基因组区域中由单倍型调节的潜在因果机制和免疫能力需要进一步研究。
